Concern about the quality of air has risen greatly in recent years. Developing means for the treatment of air for various purposes, including removing malodors, adding fragrances to the air, killing or repelling insects, and respiratory treatment, has become a major concern. This invention deals with devices for various air-treating purposes. For convenience, however, this invention and the problems which it addresses will be described primarily by reference to air fresheners.
A wide variety of devices have been developed for the dispensing of air-treating compositions. Two general approaches have been taken in dispensing air-freshening compositions: (1) spraying droplets of an air-treating liquid into the air, and (2) providing air-treating compositions on an absorbent element from which they continuously evaporate into the air over an extended period. The former method provides an instant burst of fragrance or other air-treating composition for immediate and intense air treatment. The latter method provides a continuous slow discharge of vapor to combat ambient odors.
Among the devices of the prior art used for air-treatment are those disclosed in the following U.S. Pat. Nos.:
2,520,468 (Landau)
2,987,261 (McCuiston et al.)
3,134,554 (Copley)
3,330,481 (Dearling)
3,940,024 (Russo)
3,972,473 (Harrison)
4,084,732 (Dearling)
4,235,373 (Clarke)
4,327,056 (Gaiser)
4,341,348 (Dearling)
Included in the prior art are devices intended for both instant and continuous treatment of the air. In some cases, devices of the prior art must be manipulated to achieve either an instant air treatment by discharge of a spray or recharge of a continuous air-treating element. The device described in U.S. Pat. No. 4,084,732, which is assigned to the assignee of the invention described and claimed herein, may be manipulated and adjusted for simultaneous spraying into the air and recharging of a continuous dispensing means.
The devices of the prior art have some very practical problems and disadvantages which make them ineffective and unacceptable for use in simultaneous instant/continuous air treatment.
One problem relates to the dispensing habits of air-freshener users. Many people frequently use aerosol sprays to overcome intense malodors in bathrooms and other areas, and are very accustomed to the use of aerosols for that purpose. In sharp contrast, while many people have continuous air fresheners in their homes, they generally are unaware of the manner in which they operate.
For that reason and perhaps others, rechargeable air fresheners and so-called "dual use" products which require adjustment and manipulation for different kinds of use, or for simultaneous use, are not well understood. Referring specifically to dual use products, that is, products which can be used for spraying a mist into the atmosphere or for recharging a continuous air-freshener element, many people tend to ignore the recharging use and/or do not make the necessary adjustments and manipulations to make such use possible or, if the device allows, to make simultaneous use possible.
There is a need for a product which can readily be used for both instant air treatment by spraying a mist and for recharging of a continuous-action air-treating element.
A problem which is related, at least in that it is based in part on a lack of understanding of how continuous-action air fresheners work, is that such products are infrequently changed and remain in place long beyond their periods of effectiveness. There is a need for a continuous-action air-treating product which is effective throughout the period of its use. And, there is a need for a continuous-action air-treating product which has an easily-understandable indicator marking the end of its useful life.
Another significant and very practical problem with prior so-called dual use products is that their means for dispensing air-treating liquids, for recharging a continuous-action air-treating element and for spraying into the air, do not allow proper dispensing for both purposes. For example, if dispensing for recharging purposes is proper, then serious over-saturation of the air will typically occur. And, if dispensing into the air is proper, then recharging of the continuous air-treating element will be very inadequate.
This problem will be further described. In order to make a continuous-action air-freshener element function properly, it is necessary that the concentration of the perfume in the liquid to be dispensed onto the continuous-action absorbent element be quite high. However, based on normal user habits in spraying aerosol air-fresheners and on the need for a well-distributed mist, normal spraying of such a liquid composition would result in far too strong an odor in the air.
Therefore, there is clearly a need for an improved dual-use dispensing device for air-treating compositions which will allow both proper spraying of the air to overcome intense malodors and simultaneous proper recharging of a continuous-action air-treatment element. More specifically, there is a need for such a device which, while being used to spray the air in the normal fashion to overcome intense malodors, will properly and sufficiently recharge a continous-action element such that it will function properly for the necessary extended period.